20621516 has 24 divisors (see below), whose sum is σ = 36832320. Its totient is φ = 10100432.

The previous prime is 20621443. The next prime is 20621519. The reversal of 20621516 is 61512602.

It is a junction number, because it is equal to n+sod(n) for n = 20621491 and 20621500.

It is not an unprimeable number, because it can be changed into a prime (20621519) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 59255 + ... + 59601.

It is an arithmetic number, because the mean of its divisors is an integer number (1534680).

Almost surely, 2^20621516 is an apocalyptic number.

It is an amenable number.

20621516 is a deficient number, since it is larger than the sum of its proper divisors (16210804).

20621516 is a wasteful number, since it uses less digits than its factorization.

20621516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 613 (or 611 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 20621516 is about 4541.0919391706. The cubic root of 20621516 is about 274.2248850826.

The spelling of 20621516 in words is "twenty million, six hundred twenty-one thousand, five hundred sixteen".